1. Technical Field
Embodiments of this invention generally relate to an electrophotographic image forming apparatus, such as a copier, a printer, a facsimile machine, and a multifunction peripheral (MFP) having at least two of coping, printing, facsimile transmission, plotting, and scanning capabilities.
2. Description of the Background Art
In image forming apparatuses such as printers, facsimile machines, and copiers, fluctuations in image density and color deviation arise due to environmental changes over time. Accordingly, typically, toner patterns for measurement are formed on a transfer belt, and the density and position thereof are detected.
JP-2002-207337-A proposes, at power-on time or when the number of output sheets reaches a predetermined number, forming multiple toner patterns for positional deviation adjustment on the transfer belt and adjusting positions of yellow, magenta, cyan, and black toner images. Density adjustment of respective color toner image forming units can be performed in a similar manner.
Additionally, JP-2006-293240-A proposes forming a toner pattern in a non-image area for density adjustment during formation of output images.